EP3447329A1 - Sealing arrangement - Google Patents

Abstract

The invention relates to a sealing arrangement (50) for a bellows (92) of an air spring (90), which has a bellows body (94) which consists of an elastomeric plastic with reinforcing inserts and at least one free axial end (96) an elastic annular bead (94). 98), wherein the sealing arrangement (50) has a circular connection plate (52) and a bead ring (70). For simple, fast and in particular pressure-tight connection of the bellows body (94) with the sealing arrangement (50) is provided according to the invention that the connection plate (52) and the bead ring (70) geometrically mutually correspondingly formed and arranged bayonet locking means (58, 74) , and that the annular bead (98) of the bellows (92) is designed and arranged so that it can be clamped pressure-tightly between the connection plate (52) and the bead ring (70) when closing the bayonet connection (80).

Description

The invention relates to a sealing arrangement for a bellows of an air spring, which comprises a bellows body which consists of an elastomeric plastic with reinforcing inserts and at least one free axial end has an elastic annular bead, wherein the sealing arrangement comprises a circular connecting plate and a bead ring.

Air springs are used inter alia in rail vehicles, trucks and occasionally also in passenger cars, with which a sensitive response can be realized due to a lack of self-damping, resulting in a high suspension comfort results. In addition, by means of an air suspension advantageously the vehicle height can be adjusted load-dependent, in the case of higher loads, the suspension behavior is harder.

Such air springs can be sealed by the end-side mounting a crimping plate on the air spring bellows. By reshaping the crimping plate, a bead portion of the air spring bellows is reshaped to provide a hermetically sealed pneumatic system. The disadvantage here is that process-related deviations of the crimping gap can occur and a non-destructive inspection of the crimping gap is very expensive. In addition, the opening of the air springs, for example, for maintenance, not possible. It is also known to screw the bead ring of an air spring bellows with the connection plate. For this purpose, a connection plate is screwed by means of a plurality of screws with a bead ring, which is pressed by tightening the screws of the bead area, so that also creates a hermetically sealed pneumatic system. To one To achieve reliable connection between the bead ring and the connection plate in a hermetic seal at the same time, a number of example 40 screws and possibly nuts to provide and tighten. As a result, there is a considerable increase in assembly and maintenance.

The invention therefore an object of the invention to present a sealing arrangement for a bellows of an air spring, which is easily mountable on the bellows and optionally disassembled again.

The solution to this problem is achieved with a sealing arrangement having the features of claim 1. Advantageous developments are mentioned in the dependent claims.

Accordingly, the invention relates to a sealing arrangement for a bellows of an air spring, which comprises a bellows body which consists of an elastomeric plastic with reinforcing inserts and at least one free axial end has an elastic annular bead, wherein the sealing arrangement comprises a circular connecting plate and a bead ring.

To achieve the object is hereby provided that the terminal plate and the bead ring geometrically mutually correspondingly formed and arranged bayonet locking means, and that the annular bead of the bellows is designed and arranged such that this pressure-tight between the terminal plate and the bead ring clamped when closing the bayonet connection is.

By inventively provided at least partially positive bayonet connection a circumferentially particularly uniform mechanical compression of the annular bead of the bellows with the connection plate is ensured. In addition, a simple assembly of the sealing arrangement is given. Furthermore, the bayonet connection requires a significantly reduced number of parts compared to a threaded connection. In addition, a simple and non-destructive disassembly is the Sealing arrangement for maintenance or inspection purposes possible. Furthermore, the sealing arrangement can also be used for half-bellows in rail vehicles, for bellows or rolling bellows for commercial vehicles.

According to a first development of this sealing arrangement it is provided that at the radially outer end of the connecting plate projects from this a hollow cylindrical outer wall coaxially to the bellows body that are formed on the hollow cylindrical outer wall radially inward first bayonet closure means that are formed on the bead ring radially outwardly projecting second bayonet locking means in that the first and second bayonet fastening means are lockable and arranged in the sense of a bayonet closure, that the bead ring has radially inside retaining means for holding the annular bead of the bellows, and that the retaining means is designed and arranged such that the annular bead of the bellows when closing the bayonet connection of the bead ring pressure-tight against the terminal plate is pressed.

The described compression of the annular bead of the bellows a hermetic seal of an interior of the bellows is achieved with relatively simple technical means.

In a further embodiment of the bayonet closure can be provided that are formed on the hollow cylindrical outer wall of the connection plate as the first bayonet locking means radially inwardly at least three circumferentially equally spaced apart and radially inwardly directed retaining projections. In contrast, on the bead ring as a second bayonet locking means radially outside at least three circumferentially uniformly spaced apart and radially outwardly directed locking elements are formed. As a result, the connection plate surrounds the bead ring with the free end of the bellows body arranged thereon, whereby a particularly reliable seat is provided.

Preferably, at least six peripherally equally spaced apart locking elements are on the outer wall of the connection plate and on the bead ring educated. As a result, among other things, a circumferentially particularly uniform load distribution is given.

Preferably, the bayonet connection can be converted into the locked state by an axial insertion of the bead ring into the wall region of the connection plate as well as by a relative rotational movement subsequently taking place between the bead ring and the connection plate. As a result, a quick and easy installation of the sealing arrangement is ensured on the bellows body.

Preferably, the bead ring is locked in the locked state of the bayonet connection with the connection plate. As a result, uncontrolled release of the bayonet connection is reliably prevented. Alternatively or additionally, a further anti-rotation, such as a locking pin or the like may be provided.

According to an advantageous embodiment, the latching elements for generating the axial compression of the annular bead of the bellows body on a slope with respect to a longitudinal center axis of the bayonet connection, wherein this slope is formed geometrically corresponding to a slope of the holding projections. In this way, the circumferential compression of the annular bead of the bellows body and thus the sealing effect can be further optimized.

Another technically advantageous embodiment provides that the retaining projections and the locking elements each have a circular sector-shaped geometry, wherein a circumferential distance between each two circumferentially immediately adjacent retaining projections is equal to or different from the circumferential length of the retaining projections. As a result, the bead ring can be inserted coaxially to the longitudinal central axis in the wall region of the connection plate.

According to another embodiment it can be provided that the holding means on the bead ring for holding the annular bead as a radially inwardly formed on this and in the direction of the connection plate open annular groove is formed, in which the annular bead formed at the free end of the bellows body is at least partially positively receivable. This results in an optimum position assurance of the annular bead of the bellows body, resulting in a mechanically highly resilient and hermetic seal between the bellows body and the connection plate result.

In a further technically advantageous embodiment of the sealing arrangement, the bead ring in the locked state of the bayonet connection terminates axially flush with the outer wall of the connection plate. As a result, a punctual or linear mechanical contact between the bellows of the air spring and the sealing arrangement is avoided.

• Fig. 1 eine perspektivische Ansicht einer aus dem Stand der Technik bekannten Luftfeder mit einer konventionellen Abdichtungsanordnung,
• Fig. 2 einen Teilschnitt durch die Abdichtungsanordnung gemäß Fig. 1 entlang der Schnittlinie II-II der Fig. 1,
• Fig. 3 eine Ansicht von unten auf eine Anschlussplatte einer erfindungsgemäßen Abdichtungsanordnung,
• Fig. 4 eine Ansicht von unten auf einen Wulstring der erfindungsgemäßen Abdichtungsanordnung,
• Fig. 5 eine perspektivische Ansicht der Anschlussplatte gemäß Fig. 3 zusammen mit einem koaxial ausgerichteten Wulstring gemäß Fig. 4 vor dem Erreichen eines Verriegelungszustands einer Bajonettverbindung, und
• Fig. 6 einen Teilquerschnitt durch die Bajonettverbindung gemäß Fig. 5 im verriegelten Zustand.

For a better understanding of the invention, the description is accompanied by a drawing, which will be explained below. In the drawing shows

• Fig. 1 3 is a perspective view of an air spring known from the prior art with a conventional sealing arrangement;
• Fig. 2 a partial section through the sealing arrangement according to Fig. 1 along the section line II-II of Fig. 1 .
• Fig. 3 a view from below of a connection plate of a sealing arrangement according to the invention,
• Fig. 4 a view from below of a bead ring of the sealing arrangement according to the invention,
• Fig. 5 a perspective view of the connection plate according to Fig. 3 together with a coaxially aligned bead ring according to Fig. 4 before reaching a locking state of a bayonet connection, and
• Fig. 6 a partial cross section through the bayonet connection according to Fig. 5 in the locked state.

The Fig. 1 shows a perspective view of a known from the prior art air spring 10 with two associated sealing assemblies 20, 22. Die Air spring 10 has as an essential component a largely hollow cylindrical bellows 12 with an approximately axially centrally formed constriction 14. The bellows 12 is usually formed of a rubber material or a rubber-like material, which is reinforced with reinforcing inserts. At the two axial ends 16, 18 of the bellows 12 is in each case a disc-shaped sealing arrangement 20, 22 for pneumatic sealing of the bellows 12 of the air spring 10 and for connecting the same to resilient and to be damped vehicle elements, such as a body, an axle or the like attached, the latter being not shown in the drawing. The bellows 12 have a first bellows section 26 and a second bellows section 28 on each side of the constriction 14 running centrally between the end-side sealing arrangements 20, 22, whose outer shape corresponds in each case at least substantially to that of a torus. The end-side attachment of the two sealing arrangements 20, 22 on the bellows 12 takes place here only by way of example with thirty-six screws 24 per sealing arrangement. The screws 24 make the assembly and, if necessary, a disassembly of the air spring very expensive.

Fig. 2 shows an axial partial section through the seal assembly 20 according to Fig. 1 along the section line II-II. An annular bead 30 formed at the first axial end 16 of the bellows 12 of the air spring 10 with an at least approximately semicircular cross-sectional geometry is partially received in a circumferential annular groove 32 of a bead ring 34 of the first sealing arrangement 20.

The annular groove 32 of the bead ring 34 has an approximately semicircular cross-sectional geometry for the purpose of the at least partially positive reception of the annular bead 30 of the bellows 12. The annular bead 30 of the bellows 12 is clamped axially between the bead ring 34 and a substantially disk-shaped connecting plate 36 of the first sealing arrangement 20, whereby an interior 38 of the bellows 12 is pneumatically sealed relative to the outer environment 40. In addition, the first sealing arrangement 20, which is only shown here, as well as the second sealing arrangement 22, which is not shown here, allows a sufficient amount of pressure high loadable mechanical connection between the bellows 12 of the air spring 10 and a vehicle element.

The Fig. 3 shows a view from below of a connection plate 52 of a sealing assembly according to the invention 50. This sealing assembly 50 includes, inter alia, the at least substantially cup-shaped connection plate 52 with a circular cover 54 and bottom and an integrally formed thereon hollow cylindrical outer wall 56. On the outer wall 56 are only here exemplarily radially inside six similar holding projections 58 formed as part of a bayonet connection, not shown here. These retaining projections 58 each have an approximately circular sector-shaped geometry and are each directed radially inwardly. The circumferential length L _{1 of} the retaining projections 58 is on one of these retaining projections 58 in Fig. 3 located.

Between each two in the circumferential direction of the connecting plate 52 directly adjacent retaining projections 58 is in each case a first circumferential distance U _A1 , the sum of all six circumferential distances U _A and the six circumferential lengths L _{1 of} the holding projections 58 form the inner periphery 60 of the outer wall 56 of the cup-shaped connection plate 52 of the sealing arrangement , The circumferential lengths L ₁ between the respective retaining projections 58 may be equal or unequal sized than the aforementioned circumferential distances U _A1 . Here, the circumferential lengths L _{1 are} exemplarily smaller than the circumferential distances U _A1 dimensioned. The cup-shaped connection plate 52 of the sealing arrangement 50 is furthermore designed to be rotationally symmetrical with respect to a longitudinal central axis 62 of the bayonet connection 80 to be realized.

Fig. 4 shows a view from below of a bead ring 70 of the sealing assembly according to the invention 50. The sealing assembly 50 is thus formed in two parts and has in addition to the connection plate 52 on a bead ring 70 which is rotationally symmetrical to the longitudinal central axis 62 of the bayonet joint 80 to be produced. On a solid base body 72 of the bead ring 70 are here only exemplary radially outside six similar locking elements 74 are formed. The respective ones free ends of the locking elements 74 are directed radially outward and each have a substantially circular sector-shaped geometry.

The six latching elements 74 each have a circumferential length L ₂ , which corresponds approximately to the respective circumferential distance between each two adjacent holding projections 58 of the connection plate 52 Fig. 3 corresponds to allow the axial insertion of the bead ring 70 in the wall portion of the connection plate 52 to provide the bayonet connection 80. The circumferential distance U _A2 between in each case two directly adjacent latching elements 74 of the bead ring 70 otherwise corresponds approximately to the circumferential length L _{1 of} the retaining projections 58 on the connection plate 52 Fig. 3 , In addition, the circumferential length L _{2 of} the locking elements 74 is here each greater than the circumferential distances U _A2 between each two immediately adjacent locking elements 74. Alternatively, the circumferential lengths L _{2 may be} equal to or smaller than the circumferential distances U _A2 .

Regardless thereof, the respective circumferential lengths or circumferential distances U _{A1 of} the holding projections 58 of the connection plate 52 and the circumferential lengths L ₂ and the circumferential distances U _{A2 of} the locking elements 74 of the bead ring 70 are each dimensioned in dependence on each other so that in the locked state of the bayonet connection 80 between the retaining projections 58 and the locking elements 74 sets as large as possible coverage. As a result, a sufficiently strong and permanently resilient mechanical connection between the connection plate 52 and the bead ring 70 is produced as a result.

Fig. 5 shows a perspective view of the to the terminal plate 52 according to Fig. 3 aligned bead rings 70 according to Fig. 4 prior to reaching a locking state of the bayonet joint 80. The terminal plate 52 and the bead ring 70 of the sealing assembly 50 for a bellows 12 an air spring 10 are positioned along the central longitudinal axis 62 for making a bayonet joint 80 aligned with each other, wherein the bellows 12 and the air spring 10 of the better for the sake of clarity, are not shown here. The example here six retaining projections 58th The connection plate 52 each have a first pitch S ₁ relative to the longitudinal central axis 62. The six latching elements 74 of the bead ring 70 each have a second slope S ₂ geometrically corresponding to the first-mentioned slope S ₁ . By due to the two slopes S ₁ , S ₂ in the manner of a thread interlocking retaining projections 58 and locking elements 74 is necessary to ensure a sufficient pneumatic sealing effect strong axial compression VP (see Fig. 6 ) of the bellows 92 of the air spring 90 between the terminal plate 52 and the bead ring 70 along the longitudinal central axis 62 by means of the bayonet connection 80 ensured.

To the bayonet connection 80 starting from the in Fig. 5 shown open state in the locked state ( Fig. 6 ), the bead ring 70 positioned here in alignment with the connection plate 52 is introduced into the axial wall region of the connection plate 52 coaxially with the longitudinal center axis 62 and then thereafter, as indicated by the rotation arrow 82, by a rotational movement about the longitudinal center axis 62 in a clockwise direction locked. The amount of rotation angle α required for completely locking the bayonet connection 80 depends on the respective circumferential lengths of the retaining projections 58 and the locking elements 74. The complete axial insertion of the bead ring 70 in the axial wall portion of the connection plate 52 for locking the bayonet connection 80 is in this case only possible if the locking elements 74 of the bead ring 70 are circumferentially between two immediately adjacent holding projections 58 of the connection plate 52. The unlocking and loosening of the bayonet connection 80 takes place in the reverse order.

In order to avoid an uncontrolled release of the bayonet connection 80, the bead ring 70 is locked in the locked state of the bayonet connection 80 in the connection plate 52 and locked with this. In addition, at least one unillustrated securing means may be present, such as a spring-loaded locking pin or the like, to prevent relative rotational movement between the terminal plate 52 and the bead ring 70. For this purpose, the locking pin may be biased radially inwardly by means of a spring element, so that a Loosen the bayonet connection 80, for example, for maintenance or inspection purposes, only by a radially outwardly directed extraction of the locking pin against a force applied by the spring element spring force is possible.

The Fig. 6 shows a partial cross section through the bayonet connection 80 in the locked state. An air spring 90 which is at least axially sealed on one side by means of the sealing arrangement 50 according to the invention comprises the flexible bellows 92 whose bellows body 94 consists of a fiber-reinforced elastomeric material. At a free axial end 96 of a bellows body 94, an elastic annular bead 98 is formed, which is flexible or compressible at least coaxially to the longitudinal central axis 62. The annular bead 98 has an approximately semicircular cross-sectional geometry. For at least partially positive reception of the annular bead 98 of the bellows 92 of the bead ring 70 has a circumferential annular groove 100 formed with a corresponding to the annular bead 98, that is, with a likewise approximately semi-circular cross-sectional geometry. The annular groove 100 is in this case open in the direction of the connection plate 52.

In the Fig. 6 shown bayonet joint 80 of the sealing assembly 50 is in the fully locked state, so that the retaining projections 58 of the connection plate 52 respectively engage behind the locking elements 74 of the bead ring 70 and the axial end 96 of the bellows 92 between the connection plate 52 and the bead ring 70 with the axial compression VP hermetically sealed tightly clamped. As a result, at the same time a mechanically strong in all directions high-strength connection between the bellows 92 of the air spring 90 and the seal assembly 50 is given, which, for example, to a vehicle element, not shown here, such as a body
or an axle can be connected.

Moreover, in the locked state of bayonet connection 80 shown here, bead ring 70 terminates flush with hollow cylindrical outer wall 56 of terminal plate 52 to provide a flat, axially inwardly directed abutment surface 102 which avoids any punctiform or linear mechanical contact between the bellows 92 and an end edge on the outer wall 56 of the connection plate 56. Accordingly, a further, not shown here sealing arrangement can be arranged at a second free axial end of the bellows 92 of the air spring 90.

The sealing arrangement 50 according to the invention can be mounted in a simple manner on the bellows 92 of the air spring 90 and, if necessary, dismantle several times without destruction and largely without tools. Compared to known, bolted or beaded sealing arrangements for air springs thus results in a considerably reduced installation costs.

Deviating from the air spring 90 shown here merely by way of example with the bellows 92, the sealing arrangement 50 can also be used on any air springs with rolled bellows, half bellows or the like. In addition, an application of the sealing arrangement 50 for the end-side mechanical connection of bellows, which are usually intended for sealing primarily linearly in relation to each other moved components for protection against the environment from penetrating dirt particles and / or fluids, on other machine components possible.

reference numeral

10

air spring

12

bellows

14

constriction

16

First axial end of the air spring

18

Second axial end of the air spring

20

First sealing arrangement

22

Second sealing arrangement

24

screw

26

First bellows section

28

Second bellows section

30

torus

32

ring groove

34

bead

36

connecting plate

38

Interior of the bellows

40

External environment of the bellows

50

sealing arrangement

52

connecting plate

54

Circular lid

56

Outer wall of the connection plate

58

Bayonet locking means, retaining projections

60

Inner circumference of the outer wall

62

Longitudinal central axis

70

bead

72

body

74

Bayonet locking means, locking elements

80

bayonet connection

82

rotation arrow

90

air spring

92

bellows

94

bellows body

96

Free axial end of the bellows body 90th

98

Annular bead of the bellows body 90th

100

Holding means on the bead ring, ring groove

102

Plane contact surface at the bead ring

α

angle of rotation

L ₁

Circumferential length of a holding projection

L ₂

Circumferential length of a locking element

S ₁

Slope of a holding projection

S ₂

Slope of a locking element

U _A1

Circumferential distance between two holding projections

U _A2

Circumference between two locking elements

VP

pressing

Claims (9)

A sealing arrangement (50) for a bellows (92) of an air spring (90) which has a bellows body (94) consisting of an elastomeric plastic with reinforcing inserts and has an elastic annular bead (98) at at least one free axial end (96), the sealing arrangement (50) having a circular connection plate (52) and a bead ring (70),
characterized in that the connecting plate (52) and the bead ring (70) geometrically mutually correspondingly formed and arranged bayonet locking means (58, 74), and that the annular bead (98) of the bellows (92) is designed and arranged such that this at Closing the bayonet connection (80) pressure-tight between the connection plate (52) and the bead ring (70) can be clamped. Sealing arrangement according to claim 1, characterized in that at the radially outer end of the connecting plate (52) from this a hollow cylindrical outer wall (56) coaxially to the bellows body (94) protrudes that formed on the hollow cylindrical outer wall (56) radially inward first bayonet locking means (58) in that on the bead ring (70) radially outwardly projecting second bayonet locking means (74) are formed, that the first and second bayonet locking means (58, 74) in the sense of a bayonet lock are latched together and arranged that the bead ring (70) radially inside a holding means (100) for holding the annular bead (98) of the bellows (92), and that the holding means (100) is formed and arranged such that the annular bead (98) of the bellows (92) when closing the bayonet connection of the Wulstring (70) pressure-tight against the connection plate (52) is pressed. Sealing arrangement according to claim 1 or 2, characterized in that on the hollow cylindrical outer wall (56) radially inwardly as the first bayonet closure means at least three circumferentially uniformly spaced apart and radially inwardly directed retaining projections (58) are formed. Sealing arrangement according to one of claims 1 to 3, characterized in that on the bead ring (70) radially outwardly as a second bayonet closure means at least three in the circumferential direction uniformly spaced apart and radially outwardly directed locking elements (74) are formed. Sealing arrangement according to one of claims 1 to 4, characterized in that the bayonet connection (80) by an axial insertion of the bead ring (70) in the wall region of the connection plate (52) and by a subsequently between the bead ring (70) and the connection plate (52 ) Relative rotational movement to each other in the locked state can be transferred. Sealing arrangement according to claim 5, characterized in that the latching elements (74) for generating the axial compression (VP) have a pitch (S ₂ ) with respect to the longitudinal central axis (62) of the bayonet connection (80), said pitch (S ₂ ) geometrically corresponding to a pitch (S ₁ ) of the holding projections (58) is formed. Sealing arrangement according to one of claims 1 to 6, characterized in that the holding projections (58) and the latching elements (74) each have a circular sector-shaped geometry, wherein a circumferential distance (U _A1 ) between each two peripherally immediately adjacent holding projections equal or not equal to a circumferential length ( L ₁ ) of the retaining projections (58). Sealing arrangement according to one of claims 1 to 7, characterized in that the holding means is formed on the bead ring (70) for holding the annular bead (98) as a radially inwardly formed and in the direction of the connection plate (52) open annular groove (100), in which at the free end (96) of the bellows body (94) formed annular bead (98) is at least partially positively received. Sealing arrangement according to one of claims 1 to 8, characterized in that the bead ring (70) in the locked state of the bayonet connection (80) axially flush with the outer wall (56) of the connection plate (52).

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